Bituminous emulsion



products is attempted, heavy undesirable sludges are formed. Thisinvention permits the simultaneous application of such immiscible orincompletely miscible bituminous materials with the resultant formationof a substantially homogeneous coating or binder, since the coal tar andasphalt may be dispersed in one and the same aqueous mgiiium even thoughthey are incompletely mis- Cl e.

It will, of course, be understood that the saponifying agent, aquaammonia, employed for saponifying the oleic acid in the example citedmay be added in two successive stages; that is, part to the water usedin producing the initial emulsion and part to the initial emulsionitself, instead of adding all of the aqua ammonia to the water, if sodesired, and a preferred soap may be used instead of soap-formingmaterials if preferred.

The term coal tar, as used in the specification and claims, includes rawcoal tar, dehydrated coal tar, and stripped coal tar from which aportion of the volatile constituents have been removed.

While I have described my invention herein with particular reference tothe emulsification of heavy coal tars and have referred specifically toasphalt flux oil as a bitumen suitable for use in producing the primaryemulsion to which the coal tar is added, it will be understood that myinvention is not limited to the use of these specific materials or tothe preferred forms of my invention recited herein by way ofillustration, but may be varied considerably without departing from thespirit and scope thereof.

I claim:

1. The method of producing a stable emulsion of coal tar and asphaltflux oil, the disperse phase of which emulsion contains a predominantamount of coal tar, which comprises adding 15 parts by weight of oleicacid to 250 parts by weight of asphalt flux oil, heating the mix toabout 100 C., adding the same to 750 parts of water to which have beenadded 34 parts of aqueous ammonia whereby an emulsion of the asphaltflux oil which has a viscosity substantially greater than that of wateris produced, thereafter adding 1500 parts by weight of coal tar whichhas a specific gravity of about 1.18 or more heated to a temperature ofabout 70 C. to which has been added 45 parts of oleic acid, vigorouslyagitating said tar with the emulsion of asphalt flux oil, and subjectingthe resulting mixed emulsion to intensive mechanical disintegration, asfor example by passage through a colloid mill.

2. A stable asphalt-coal tar emulsion comprising from to 34 per centasphalt, 36 to 60 per cent coal tar, 28 to 43 per cent water, and asmall amount of a salt of a. higher fatty acid as the emulsifying agent.

3. A method of producing a stable emulsion of coal tar and petroleumasphalt, the disperse phase of which emulsion contains a predominantamount of coal tar, which comprises mixing from 1.25 to 2.5 parts byweight of oleic acid with about 8 parts by weight of petroleum asphalthaving a melting point of from 105 to 120 F. (ring and ball method),adding this mixture while stirring to about 30 parts by weight of hotwater containing ammonia in an amount more than sufiicient to neutralizethe oleic acid, thus forming an emulsion of asphalt in water, andgradually adding to this emulsion about 60 parts by weight of liquefiedcoal tar having a melting point of approximately 80 F.

4. A bitumen emulsion comprising from 10 to 34 per cent of easilyemulsifiable asphaltic bituminous material, from 36 to 60 per cent ofcoal tar having a specific gravity of about 1.15 or higher at 25 C.,from 28 to 43 per cent of water, and a small amount of a salt of ahigher fatty acid as the emulsifying agent.

5. The method of producing a substantially stable dispersion containingas the disperse phase a relatively large amount of tar of the groupconsisting of coal tar and water gas tar of a specific gravity of atleast 1.15 and a smaller amount of asphalt, which comprises producing aninitial dispersion containing an aqueous medium, soap and a relativelysmall amount of asphalt and thereafter dispersing tar of the groupconsisting of coal tar and water gas tar in amount greater than theamount of asphalt directly in said initial dispersion.

6. A substantially stable dispersion of asphaltic bitumen and tar of thegroup consisting of coal tar and water gas tar in an aqueous medium, thedisperse phase of said dispersion containing a minor proportion ofasphaltic bitumen and a major proportion of tar of the group consistingof coal tar and water gas tar, said dispersion containing at least about28 percent of water and an emulsifying agent.

7. The process of producing a stable dispersion, the disperse phase ofwhich is constituted predominantly of tar of the group consisting ofcoal tar and water gas tar, in an aqueous medium, comprising producingan initial emulsion containing a relatively small amount of asphalticbitumen in an aqueous dispersing medium, and an emulsifying agent, andadding an amount of tar of the group consisting of coal tar and watergas tar greater than the amount of said asphaltic bitumen to saidinitial emulsion to form the said stable dispersion, the disperse phaseof which is predominantly constituted of said tar.

FRANCIS FAIR, JR.

Patented July 2Q, 1937 PROCESS OF MAKING BITUMINOUS EMULSIONS William F.Fair, J12, New York, N. Y., assignor to The Barrett Company, New York,N. Y., a corporation of New Jersey Application February 9, 1934,

No Drawing.

Serial No. 710,533

2 Claims.

This invention relates to emulsions or dispersions of bituminousmaterials, and more particularly, to coal tar emulsions and methods forproducing the same.

5 Heretofore, emulsions of asphalts have been made and used forsurfacing roads, curing concrete, protecting iron Work, etc. In someinstances, light tars have also been emulsified. Heavy coal tars, thatis coal tars having a specific 10 gravity of from 1.18, or even as loWas 1.15, to

1.25 or higher 'at'25 C. have not been successfully used in producingemulsions prior to the invention of my copending application Serial No.

628,113, filed August 9, 1932, for the reason that 15 emulsions of suchtars when produced by processes such as are used in producing asphalticemulsions are relatively unstable so that the tar soon settles out ofsuspension.

Coal tars generally are of higher specific gravity than asphalts andthis property may account, in part at least, for the comparativeinstability of emulsions or dispersions of coal tars as heretoforeproduced. Among the factors which influence the stability of emulsionsand tend to cause settling out of the material dispersed are differencesin density of the disperse phase and the continuous phase anddifferences in viscosity of the two phases or a combination of thesefactors with others. It has been pro- 30 posed to increase the stabilityof emulsions or dispersions of bituminous materials by (1) increasingthe density of the aqueous phase and (2) by decreasing the density ofthe disperse phase.

Method (1) has been practiced heretofore by J adding clay or the like tothe aqueous phase prior to the dispersion of the bituminous material.

However, the resulting dispersion then contains undesired inertinorganic material. Method (2) has been used by cutting back thebituminous 40 material with a sunicient amount of a light organicsolvent to reduce the density and viscosity of the material dispersed.This method, it will be noted, requires the use of substantial amounts 1of relatively expensive solvents and changes the 45 physical propertiesof the bituminous phase.

Among the objects of this invention are to produce bituminous emulsionsof improved stability, and particularly, coal tar emulsions ordispersions of improved stability; to provide an in- 50 expensive andsimple method by which such emulsions or dispersions can be made and toproduce such emulsions Without incorporating objectionable inertinorganic materials therein. These and other objects of this inventionwill appear 55 from the following description thereof.

In my copending application, hereinabove referred to, there is discloseda procedure of making coal tar emulsions involving the formation of aninitial emulsion by dispersing a relatively small amount of a suitableeasily-emulsifiable 5 bituminous material, such as asphalt, in anaqueous medium and then adding to this initial emulsion relatively heavycoal tar or water gas tar. Asphalts, asphalt flux oil, petroleum, fueloil, or other asphaltic or petroleum bitumens may be employed as thebituminous material for the disperse phase of the initial emulsion.Preferably, asphalt having a penetration at 77 F. of

from 100 to 220 tenths of a millimeter (determined by A. S. T. M.Standard Method D5-25) is utilized. A relatively heavy coal tar having aspecific gravity of not less than 1.15 at 25 C. and a viscosity of notless than approximately 60 seconds for 100 c. c. at 199 C. or arelatively heavy water gas tar having a viscosity of not less thanapproximately 60 seconds per 100 c. c. at 100 C. is dispersed in theinitial emulsion. Heavier and more viscous coal tars, including cokeoven, vertical and horizontal retort tars, Water gas tar, or otherrelatively heavy bituminous material of different characteristics fromthat forming the disperse phase of the initial emulsion may be added tothe initial emulsion.

In producing such emulsions, preferably a soap or saponaceous materialis employed as a dispersing agent to aid in the production of both theinitial and the final emulsion. The soapforming materials may be addedto the aqueous medium and to the bituminous material to be dispersed sothat a reaction between the soapforming materials which results in theformation of soap takes place during the emulsification of thebituminous material. Preferably, the basic constituent of the soap isadded to the aqueous medium in which it is readily soluble and theacidic constituent is added to. the material to be dispersed, although,if desired, the soap emulsifier, as such, or soap-forming constituentsmay be added to the emulsion during its formation or immediately afterthe addition of the bituminous material to the aqueous medium and duringthe agitation of the mixture. Ammonium or sodium soaps of fatty acids ormixtures of fatty acids, sodium resinate, the reaction product of sodiumsilicate and oleic acid, the sodium salts of sulfonated coumarone resinand associated sulfcnated coumarone-like compounds or the sodium saltsof other sulfonated benzene derivatives may be employed as dispersingagents.

Emulsions of asphalts and readily emulsifiable 5

